1. Field of the Invention
The present invention relates to the field of footwear, and most particularly to athletic footwear of the type having a rubber sole (e.g., a "sneaker" or "tennis shoe").
2. Description of the Related Art
U.S. Pat. No. 4,995,173 relates to an article of footwear incorporating a foot actuated pump which is connected to one or more expandable air bladders located in portions of the footwear where contour fitting is desired, and an adjustable relief valve connected to the bladder for releasing air therefrom when a preselected pressure is exceeded.
U.S. Pat. No. 4,009,528 relates to a canvas shoe having an insole that includes a soft pad encased in a sealed film envelope to prevent the absorption of moisture and odors. The envelope includes a chamber disposed without and above the toe portion into which air is expelled by pressure applied by the weight of the wearer.
U.S. Pat. No. 3,556,486 relates to an athletic sneaker having a wedge extending from the heel to just behind the metatarsal heads, an inner heel pad positioned over the wedge, and an outside pad extending three eighths the length of the wedge.
Finally, U.S. Pat. Nos. 319,718 and 273,628 relate to ornamental designs for sneakers.